HP XC System Software Administration Guide Version 3.0

8. Distributing Software Throughout the System
This chapter addresses the following topics:
Overview of the Image Replication and Distribution Environment (page 79)
Adding Software or Modifying Files on the Golden Client (page 80)
Determining Which Nodes Will Be Imaged (page 83)
The Golden Image Checksum (page 83)
Updating the Golden Image (page 84)
Propagating the Golden Image to All Nodes (page 86)
Maintaining Service Configuration Globally (page 88)
Overview of the Image Replication and Distribution Environment
The image replication and distribution environment is responsible for keeping the software on all client nodes
synchronized with the golden client. The image replication and distribution environment is automatically
configured on the HP XC system during the initial cluster configuration step, which is described in the
HP
XC System Software Installation Guide
.
Image replication and distribution environment involves the following concepts:
Golden client
The node from which a standard file system image is created.
The golden client represents the configuration from which all other nodes are replicated.
In terms of hardware, the golden client should be representative of (ideally, identical
to) all nodes in the system.
The head node is the golden client in the HP XC system.
Golden image
A collection of files, created from the golden client file system, to be distributed to one
or more client systems. You can exclude specific files on the golden client from the
golden image if they are not appropriate for replication. The golden image is a
replication of the golden client's local file systems, starting from the root directory (/).
Note
The golden image should contain only those files and directories that are appropriate
for distribution to all client nodes. The golden image should be free of node-specific
content, such as node-specific subdirectories of /var.
Exclusion files list files and directories to exclude from the golden image; these files
are discussed in “Exclusion Files” (page 85).
Image server
The node specifically designated to hold the images to be distributed to client systems.
The image server distributes the golden image.
The head node is the image server in the HP XC system.
You synchronize client nodes to the golden client by distributing the golden image. When you use the
si_updateclient command to update nodes with a new golden image, only files that have changed in
the golden image between the current installation and the new image are distributed; this saves time and
network bandwidth.
This chapter describes how to manage the image replication and distribution environment, and how to use
it to distribute software (including configuration changes) to all cluster nodes. The basic procedure is as
follows:
1. Install software or modify files on the golden client. See Adding Software or Modifying Files on the
Golden Client” (page 80).
2. Update the golden image. See “Updating the Golden Image” (page 84).
3. Distribute the golden image or individual files to the client nodes. See “Propagating the Golden Image
to All Nodes” (page 86).
Overview of the Image Replication and Distribution Environment 79